Electrical apparatus for obtaining printing light intensity values

ABSTRACT

Electrical apparatus for obtaining light intensity values for printing lights for use with a production color film by comparing density values of a standard color film and light intensity values for printing lights for use with the standard color film with density values of the production color film, said apparatus having visual indicators for displaying the obtained light intensity values for the printer lights for the production color film. A computation circuit is electrically connected to the visual indicators and to a standard color film circuit and to a standard lamp level circuit and to a production color film circuit for electrically processing signals from a plurality of potentiometers in the respective circuits. The signals represent density values associated with the standard color film and the production color film and light intensity values associated printer lights for the standard color film whereby when the computation circuit is activated, numerical intensity values for the printer lights for the production color film are displayed by the visual indicators. A conversion circuit is electrically connected to the computation circuit for producing signals in selected increments of printer light intensities.

United States Patent [72] lnventors John V. Hanline Kansas City, Mo.;

Daniel M. Chopin, Shawnee Mission, lions. [21] Appl. No. 835,143 [22] Filed June 20, 11969 [45] Patented [73] Assignee Nov. 116, 1971 Film Equipment Manufacturing Co. Kansas City, Mo.

[54] ELECTRICAL APPARATUS FOR OBTAINHNG PRINTING LIGHT lNTENSlTY VALUES 9 Claims, 3 Drawing Figs.

Primary Examiner-Joseph F. Ruggiero Attorney-Fishburn, Gold and Litman ABSTRACT: Electrical apparatus for obtaining light intensity values for printing lights for use with a. production color film by comparing density values of a standard color film and light intensity values for printing lights for use with the standard color film with density values of the production color film, said apparatus having visual indicators for displaying the obtained light intensity values for the printer lights for the production color film. A computation circuit is electrically connected to the visual indicators and to a standard color film circuit and to a standard lamp level circuit and to a production color film circuit for electrically processing signals from a plurality of potentiometers in the respective circuits. The signals represent density values associated with the standard color film and the production color film and light intensity values associated printer lights for the standard color film whereby when the computation circuit is activated. numerical intensity values for the printer lights for the production color film are displayed by the visual indicators. A conversion circuit is electrically connected to the computation circuit for producing signals in selected increments of printer light intensities.

PATENTEDunv 1s l97l SHEET 1 BF 2 INVENTORS V. HOHHHQ a M a h C M M m a P B John TTOR N E Y5 lELEC'lllltlCAL APPARATUS FOR OBTAHNING PRINTHNG lLll Gll-llT lNTENSiTY VALUES The present invention relates to photographic apparatus and more particularly to electrical apparatus for comparing density values of a standard color film and printer light intensity values for use with the standard color film with density values of a production color film to obtain intensity values for printer lights for use with the production color film.

The principal objects of the present invention are: to provide an electrical apparatus for simultaneously determining and visually displaying intensity values for printer lights for use with a production color film; to provide such an electrical apparatus adapted to compare respective density values of a standard color film and printer light intensity values for printer lights associated therewith with density values of a production color film to obtain intensity values for printer lights for use with the production color film; to provide such an electrical apparatus adapted to provide results equal to solution of the equation K (D D,+l,)=l wherein D and D are red and green and blue density values of the standard color film and the production color film respectively and I, and 1 are the red and green and blue light intensity values of printer lights for use with the standard color film and the production color film respectively and K is a coefficient for each color to convert the intensity values to a convenient range; and to provide such an electrical apparatus which is economical to manufacture, easily maintained, positive and direct in operation, and particularly well-suited for the proposed use.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this inventron.

FlG. l is a perspective view of a cabinet containing an electrical apparatus for obtaining intensity values for production printer lights embodying features of the present invention.

FIG. 2 is a wiring diagram of the electrical apparatus for obtaining the production printer light intensity values with the essential operating parts diagrammatically shown.

FIG. 3 is a detailed wiring diagram of a computation circuit for the electrical apparatus.

Referring more in detail to the drawings:

The reference numeral 1 generally designates a cabinet for containing electrical apparatus 2 for obtaining light intensity values for printer lights (not shown) for use with a production color film (not shown). The electrical apparatus 2 has a plurality of adjustable potentiometers, each adapted to produce a signal having a coded value responsive to adjustment thereof and a computation circuit 3 electrically connected to the potentiometers for processing the signals therefrom.

The electrical apparatus 2 has visual indicators d, 5 and b electrically connected to the computation circuit 3 for displaying numerical values representing results of processing the potentiometer signals with the numerical values displayed representing red, green and blue light intensity values respectively for printer lights for use with the production color film. A computation reference source 7 is electrically connected to the potentiometers and is adapted to produce a reference signal of substantially constant intensity for comparing the reference signal with each of the potentiometer signals.

Potentiometers b, 9 and 10 are arranged in a standard color film circuit ll and each is adapted to produce a signal responsive to adjustment thereof representing red, green and blue density values respectively of a standard color film (not shown). It is desirable to have a wide range of red density values available, therefore, a switch i2 is operatively connected to electrical elements which are operative to multiply the potentiometer signals by a selected multiple, such as ten (10).

Calibration potentiometers 13, id and 115 are connected to the adjustable potentiometers 8, 9 and 10 respectively and to the computation circuit 3 for maintaining precision operation of the electrical apparatus 2. A calibration potentiometer 16 is connected to the switch 12 and to the computation circuit 3 for precise adjustment of the multiplier signal.

The potentiometers h, '39 and it) are adjusted by knobs 117, lb and 39 respectively, which have dials i7, 118 and i9 respectively for visually displaying numerical values responsive to the adjustment of the respective potentiometer. In the illustrated electrical apparatus, the dials 17. m and 119 associated with the knobs 117, w and i9 display numerical values representing red, green and blue density values respectively of a standard or control color film (not shown).

The potentiometers h, 9 and are mounted in series between conductors 20 and 21 which are electrically connected to the computation reference source 7 whereby, when the electrical apparatus 2 is activated by a pushbutton 22, the potentiometers b, 9 and it) will produce signals which are representative of the density values of red, green and blue respectively of the standard color film (not shown).

Potentiometers 23 24 and 25 are arranged in a standard lamp level circuit 26 with the potentiometers 23, 2d and 25 being adjusted by knobs 27, 28 and 2% respectively which have dials 27', 28 and 29 respectively for visually displaying red, green and blue light intensity values for printer lights (not shown) for the standard color film or control film. Calibration potentiometers 3t), 3i and 32 are connected to the adjustable potentiometers 23, 2 5 and 25 respectively for maintaining precision operation of the standard lamp level circuit 26.

in the illustrated electrical apparatus 2, the potentiometers 23, 2d and 25 are connected in series between conductors 33 and 1% which are also connected to the computation reference source '7 for producing signals representing the red, green and blue light intensity values respectively of the printer lights (not shown) for use with the standard control film.

Potentiometers 35, 36 and 37 are arranged in a production color film circuit 33 and are adjusted by ltnobs 39, 4m and M respectively which have dials 39', MB and M respectively to visually display numerical values representing the adjustment of the respective potentiometers. Calibration potentiometers d2, A3 and M are connected to the adjustable potentiometers 35, 36 and 37 respectively for maintaining precision operation of the production color film circuit 38. A switch 15 is operatively connected to a calibration potentiometer for multiplying the potentiometer signals by the same multiple as in the standard color film circuit ill. in the illustrated electrical apparatus, the potentiometers 35, 36 and 37 are electrically connected in series between conductors 4'7 and 38 which are electrically connected to the computation reference source 7.

Adjustable potentiometers d9, 50 and 5B are arranged in a conversion circuit 52. The potentiometers d9, 50 and 511 are adjusted by knobs 53, 5d and 55 respectively which have dials 53', 5d and 55 for visually displaying numerical values representing the adjustment of the respective potentiometer. in the illustrated electrical apparatus, the dials 53', 5d, and 55' display a numerical coefficient for converting potentiometer signals to usable increments of selected light intensity for printer lights for use with the production color film. The adjustable potentiometers 39, 5d and 5B are connected to the red, green and blue channels 49, 5b and fill respectively of the computation circuit, as later described.

The computation circuit 3 is adapted to electrically sum positive and negative signals from the red potentiometers 8, 23 and 35 and from the green potentiometers 9, 2d and 36 and from the blue potentiometers it 2d and 37 to produce net signals for processing in the computation circuit 3. The respective net signals in the red, green and blue channels 49'', $0" and fill" respectively are modified by the adjustable potentiometers 49, 5t!) and 5 5. respectively.

The computation circuit 3 includes a portion to receive the net signal associated with the respective primary colors and has a red channel, green channel and blue channel 49, 50' and 51 respectively with a power source 56 electrically connected to a power supply, such as a plug 56', and to operational amplifiers 57, 58 and 59 in the red, green and blue channels 49', $0 and fil respectively. A conductor 60 extends between a neutral conductor 61 of the power source 56 and the operational amplifiers 7, 58 and 59 with resistors 62, b3 and 64 being electrically connected between conductor 60 and noninverting inputs of the operational amplifiers 57, 58 and 59 respectively. The resistors 62, 63 and 64 are each in the nature of 30 kohm, [/4 w., or 5 percent resistors.

Ofi'set balancing potentiometers 65, 66 and 67 are associated with the operational amplifiers 57, 58 and 59 respectively with the potentiometers 65, 66 and 67 each being in the nature of 2.5 k. ohm potentiometers and being connected to the power source 56 by conductors 68 and 69.

Amplification completion loops 70, 71 and 72 are associated with the red, green and blue channel operational amplifiers 57, 58 and 59 respectively with capacitors 73, 74 and 75 being positioned in the amplification completion loops 70, 71 and 72 respectively to average the input to substantially reduce noise in the respective color channels of the computation circuit 3. The adjustable potentiometers 49, 50 and 51 are connected to connection points 76 and 77 on opposite sides of the capacitors 73, 74 and 75 to control the gain of the red, green and blue operational amplifiers 57, 58 and 59 respectively.

A set of three resistors 78, 79 and 80 are connected to the respective operational amplification completion loops 70, 71 and 72 respectively and are in the nature of 196 k. ohm, onefourth w, or 1.0 percent resistors. A set of the resistors 78, 79 and 80 is connected to the standard color film circuit 11, the standard lamp level circuit 26 and the production color film circuit 38.

Resistors 81 and 82 are connected to the calibration potentiometers 16 and 46 in the standard color film circuit 11 and in the production color film circuit 38 respectively and to the red amplification loop 70.

The amplification completion loops 70, 71 and 72 are connected to output conductors 83, 84 and 85 respectively whereby voltage in the output conductor 83 represents the intensity of the red-printing light for the production color film and the voltage in the output conductors 84 and 85 represents intensities of the printing lights for the green and blue channels respectively.

A switch 86 is positioned on a cabinet front panel 87 and is movable between an "on and "off" position to supply electrical power to the computation reference source 7 and the power source 56. The computation reference source 7 is adapted to produce a substantially constant output reference signal, such as in the nature ofior 1000 volts. Manipulation or adjustment of the various knobs varies respective resistances in the respective potentiometers whereby, when the reference signal passes through the respective potentiometers, a signal is produced having a value responsive to adjustment thereof with the potentiometer signals representing respective film density and light intensity values. The potentiometer signals are electrically summed for each of the red, green and blue channels whereby a net signal (voltage) is presented to the computation circuit 3 for processing.

It is desirable to have the electrical apparatus 2 self-calibrating, therefore, a calibration circuit 88 is electrically connected to the computation circuit 3 and to the visual indicators 4, 5 and 6.

The electrical apparatus 2 is adapted to provide results equivalent to those obtainable by solving the equation K (D D +l,)=l for each color channel wherein D is red, green and blue density values of the standard color film or control film and D is the red, green 'and blue density values of the production color film. I is the red, green and blue intensity values of printer lights for use with the control film. I, is the desired light intensity values for printer lights for use with the production color film and I is the intensity values displayed on the visual indicators 4, 5 and 6 respectively. K is a different coefficient for each color channel representing characteristics of respective layers of emulsion or the like on color-sensitive material, such as color film or printing paper. K may be the product of several numerical values each representing respective elements in the processing of color film and printing paper, such as quality and thickness of emulsion layers, quality of dyes, operating efficiency of printing apparatus and the like. K is a multiplier and the values obtained from electrically processing the respective signals represent printing light intensity values. In printing apparatus (not shown) using printing lights, the flux or intensity of the lights increases in convenient steps and electrically processing the respective signals designates a particular step of flux for use with a production color film in making a print therefrom.

An optimum color print is made from the standard color film or the control film and the density values of the standard color film obtained by using a densitometer (not shown). The density values for the standard color film and the light intensity values of the printer lights used in making the color print are placed in the electrical apparatus 2 by adjusting the potentiometers 8. 9 and 10 and the potentiometers 23, 24 and 25 respectively whereby v the respective dials display values representing the red, green and blue density values of the standard color film and the red, green and blue intensity values of the printer lights used therewith for making the optimum color print. A production color film from which it is desired to make a color print having color characteristics corresponding to the optimum color print made from the standard color film and its printer lights is placed in a densitometer (not shown) to obtain the red, green and blue density values thereof which are then placed in the electrical apparatus 2 by adjustment of the potentiometers 35, 36 and 37 respectively. The adjustable potentiometers 49, 50 and 51 are each adjusted to the selected coefiicient for the respective colors with the dials 53', 54 and 55' displaying numerical values representing the respective coefiicients. The pushbutton 22 is then depressed to activate the computation circuit 3 which processes the signals from the respective potentiometers in the circuits 11, 26, 38 and 52 to visually display numerical values on the visual indicators 4, 5 and 6 representing intensity values for printer lights for use with the production color film having the density values represented by the signals produced by the potentiometers 35, 36 and 37.

It is to be understood that while we have illustrated and described one form of our invention, it is not to be limited to the specific form or arrangement of parts herein described and shown.

What we claim and desire to secure by Letters Patent is:

1. Electrical apparatus for obtaining printing light intensity values for use in making a print from a production color film, the electrical apparatus comprising:

a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof, said potentiometers being arranged in a color film density circuit with said potentiometers thereof arranged in a plurality of channels and a lamp level circuit with said potentiometers thereof arranged in a plurality of channels and a production color film density circuit with said potentiometers thereof arranged in a plurality of channels and each of said circuits having a channel for each of the primary colors of red and green and blue, said plurality of potentiometers in said color film density circuit being operative to produce signals representing selected density values of a control color film, said plurality of potentiometers in said lamp level circuit being operative to produce signals representing selected intensity values of printer lights for use with said control color film, said plurality of potentiometers in said production color film density circuit being operative to produce signals representing selected density values of a production color film;

b. a computation circuit electrically connected to said potentiometers in said channels of said circuits for processing said signals therefrom;

c. electric power means electrically connected to said computation circuit for activating same; and

d. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing printer light intensity values for use in making a print from a production color film.

2. The electrical apparatus as set forth in claim 1 including:

a. a conversion circuit electrically connected to said computation circuit, said conversion circuit being operative to produce signals in selected increments.

3. The electrical apparatus as set forth in claim 2 wherein:

a. said potentiometers in said channels in said color film density circuit are operative to produce signals representing density values for the primary colors of red and green and blue;

b. said potentiometers in said channels in said production color film density circuit are operative to produce signals representing density values for the primary colors or red and green and blue;

c. said potentiometers in said channels in said lamp level circuit are operative to produce signals representing intensity values for the primary colors of red and green and blue; and

d. said computation circuit is operative to electrically sum said potentiometer signals for each of the respective colors and electrically convert said electrical summations to signals representing selected increments of light intensity values for red and green and blue printer lights for the production color film.

t. The electrical apparatus as set forth in claim 3 wherein said computation circuit includes:

said conversion circuit includes:

at an adjustable potentiometer for the channel for each of said primary colors and connected to the operational amplifier for the channel for the respective primary color; and

b. visual display means operatively connected to each of said adjustable potentiometers for displaying numerical values representing the adjustment thereof.

6. The electrical apparatus as set forth in claim 5 wherein:

a. said potentiometer signals are generated by means of digital circuits in said standard color film density circuit and said production color film density circuit;

b. said potentiometer signals of the potentiometers in said standard lamp level circuit are each generated by digital means to represent said respective light intensity values; and

. said computation circuit processes said signals in a digital manner.

7. The electrical apparatus as set forth in claim n including: a. display means operatively connected to each of said digital generators in said standard color film density circuit and in said production color film density circuit for displaying numerical values representing adjustment of said respective digital generators, said numerical values representing respective density values of the standard color film and the production color film; and b. display means operatively connected to each of said digital generators in said standard lamp level circuit for displaying numerical values representing adjustment of said respective generators, said numerical values representing respective printer light intensity values for use in making a print from a standard color film. 8. Electrical apparatus for obtaining printing light intensity values for use in making a print from a production color film,

the electrical apparatus comprising:

a. a plurality of ad ustable potenttometers each operative to produce a signal having a value responsive to adjustment thereof;

b. A computation circuit electrically connected to said potentiometers for processing said signals therefrom;

c. electric power means electrically connected to said computation circuit for activating same;

a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing printer light intensity values for use in making a print from a production color film; and

e. a computation reference source operative to produce a reference signal of substantially constant intensity for comparing each potentiometer signal therewith.

9. Electrical apparatus for obtaining printing light intensity values for use in making a print from a production color film, the electrical apparatus comprising:

a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof;

b. a plurality of circuits each having a plurality of said potentiometers therein arranged in a plurality of channels;

c. a calibration potentiometer for each of the potentiometers in certain of the circuits;

d. a computation circuit electrically connected to said potentiometers in said channels of said circuits for processing said signals therefrom;

e. electric power means electrically connected to said computation circuit for activating same; and

. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing printer light intensity values for use in making a print from a production color film. 

1. Electrical apparatus for obtaining printing light intensity values for use in making a print from a production color film, the electrical apparatus comprising: a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof, said potentiometers being arranged in a color film density circuit with said potentiometers thereof arranged in a plurality of channels and a lamp level circuit with said potentiometers thereof arranged in a plurality of channels and a production color film density circuit with said potentiometers thereof arranged in a plurality of channels and each of said circuits having a channel for each of the primary colors of red and green and blue, said plurality of potentiometers in said color film density circuit being operative to produce signals representing selected density values of a control color film, said plurality of potentiometers in said lamp level circuit being operative to produce signals representing selected intensity values of printer lights for use with said control color film, said plurality of potentiometers in said production color film density circuit being operative to produce signals representing selected density values of a production color film; b. a computation circuit electrically connected to said potentiometers in said channels of said circuits for processing said signals therefrom; c. electric power means electrically connected to said computation circuit for activating same; and d. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing printer light intensity values for use in making a print from a production color film.
 2. The electrical apparatus as set forth in claim 1 including: a. a conversion circuit electrically connected to said computation circuit, said conversion circuit being operative to produce signals in selected increments.
 3. The electrical apparatus as set forth in claim 2 wherein: a. said potentiometers in said channels in said color film density circuit are operative to produce signals representing density values for the primary colors of red and green and blue; b. said potentiometers in said channelS in said production color film density circuit are operative to produce signals representing density values for the primary colors or red and green and blue; c. said potentiometers in said channels in said lamp level circuit are operative to produce signals representing intensity values for the primary colors of red and green and blue; and d. said computation circuit is operative to electrically sum said potentiometer signals for each of the respective colors and electrically convert said electrical summations to signals representing selected increments of light intensity values for red and green and blue printer lights for the production color film.
 4. The electrical apparatus as set forth in claim 3 wherein said computation circuit includes: a. an operation amplifier for the channel for each of said primary colors; b. balancing means electrically connected to each of said operational amplifiers for balancing current therethrough; c. circuit noise reduction means electrically connected to each of said operational amplifiers; and d. a plurality of resistors electrically connected to each of said operational amplifiers.
 5. The electrical apparatus as set forth in claim 4 wherein said conversion circuit includes: a. an adjustable potentiometer for the channel for each of said primary colors and connected to the operational amplifier for the channel for the respective primary color; and b. visual display means operatively connected to each of said adjustable potentiometers for displaying numerical values representing the adjustment thereof.
 6. The electrical apparatus as set forth in claim 5 wherein: a. said potentiometer signals are generated by means of digital circuits in said standard color film density circuit and said production color film density circuit; b. said potentiometer signals of the potentiometers in said standard lamp level circuit are each generated by digital means to represent said respective light intensity values; and c. said computation circuit processes said signals in a digital manner.
 7. The electrical apparatus as set forth in claim 6 including: a. display means operatively connected to each of said digital generators in said standard color film density circuit and in said production color film density circuit for displaying numerical values representing adjustment of said respective digital generators, said numerical values representing respective density values of the standard color film and the production color film; and b. display means operatively connected to each of said digital generators in said standard lamp level circuit for displaying numerical values representing adjustment of said respective generators, said numerical values representing respective printer light intensity values for use in making a print from a standard color film.
 8. Electrical apparatus for obtaining printing light intensity values for use in making a print from a production color film, the electrical apparatus comprising: a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof; b. A computation circuit electrically connected to said potentiometers for processing said signals therefrom; c. electric power means electrically connected to said computation circuit for activating same; d. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing printer light intensity values for use in making a print from a production color film; and e. a computation reference source operative to produce a reference signal of substantially constant intensity for comparing each potentiometer signal therewith.
 9. Electrical apparatus for obtaining printing light intensity values for use in making a print from a production color film, the electricaL apparatus comprising: a. a plurality of adjustable potentiometers each operative to produce a signal having a value responsive to adjustment thereof; b. a plurality of circuits each having a plurality of said potentiometers therein arranged in a plurality of channels; c. a calibration potentiometer for each of the potentiometers in certain of the circuits; d. a computation circuit electrically connected to said potentiometers in said channels of said circuits for processing said signals therefrom; e. electric power means electrically connected to said computation circuit for activating same; and f. a plurality of visual indicators electrically connected to said computation circuit for displaying numerical values representing results of processing the potentiometer signals, said numerical values representing printer light intensity values for use in making a print from a production color film. 